Four-row cylindrical roller bearings are not new per se.
In the known four-row cylindrical roller bearings used to support the rolls in roll stands, the outer ring is provided with fixed flanges, and the inner ring is flangeless. There are also split outer ring designs wherein the two parts of the outer ring are provided with flanges and the inner ring is flangeless. In addition, each pair of adjacent rows of rollers is guided by a common cage as shown in West German Pat. No. 1,775,013.
These known designs have the disadvantage that, especially at high speeds, the rollers no longer roll properly in any of the rows, which means that, as a result of slippage and sticking damage can occur. These same forms of damage occur when, as a result of the common cage, the individual rows of rollers cannot roll along at the different peripheral velocities resulting from the different load relationships on the individual rows of rollers. The cage may be destroyed by the damage caused by this slippage. Finally, it requires great effort to remove and reinstall the known bearings when the rolls have to be reground, a frequent occurrence.